Diagnostic efficacy of gadoxetic acid (Primovist)-enhanced MRI and spiral CT for a therapeutic strategy: comparison with intraoperative and histopathologic findings in focal liver lesions

Abstract

A multicenter study has been employed to evaluate the diagnostic efficacy of magnetic resonance imaging (MRI) using the new liver-specific contrast agent gadoxetic acid (Gd-EOB-DTPA, Primovist), as opposed to contrast-enhanced biphasic spiral computed tomography (CT), in the diagnosis of focal liver lesions, compared with a standard of reference (SOR). One hundred and sixty-nine patients with hepatic lesions eligible for surgery underwent Gd-EOB-DTPA-enhanced MRI as well as CT within 6 weeks. Pathologic evaluation of the liver specimen combined with intraoperative ultrasound established the SOR. Data sets were evaluated on-site (14 investigators) and off-site (three independent blinded readers). Gd-EOB-DTPA was well tolerated. Three hundred and two lesions were detected in 131 patients valid for analysis by SOR. The frequency of correctly detected lesions was significantly higher on Gd-EOB-DTPA-enhanced MRI compared with CT in the clinical evaluation [10.44%; 95% confidence interval (CI): 4.88, 16.0]. In the blinded reading there was a trend towards Gd-EOB-DTPA-enhanced MRI, not reaching statistical significance (2.14%; 95% CI: -4.32, 8.6). However, the highest rate of correctly detected lesions with a diameter below 1 cm was achieved by Gd-EOB-DTPA-enhanced MRI. Differential diagnosis was superior for Gd-EOB-DTPA-enhanced MRI (82.1%) versus CT (71.0%). A change in surgical therapy was documented in 19 of 131 patients (14.5%) post Gd-EOB-DTPA-enhanced MRI. Gd-EOB-DTPA-enhanced MRI was superior in the diagnosis and therapeutic management of focal liver lesions compared with CT.